Use of the centers for disease control and prevention childhood lead poisoning risk questionnaire to predict blood lead elevations in pregnant women

Abstract

To assess the accuracy of a questionnaire developed by the Centers for Disease Control and Prevention (CDC), given to pregnant women for identification of children at risk for lead poisoning. The study population consisted of all 314 new prenatal patients enrolled in health department clinics in 1990-1992. Lead was measured in venous blood, and patients completed written questionnaires to gather information about lead exposure risk factors. The relationship between elevated maternal blood lead levels (at or greater than 10 micrograms/dL or 0.483 mumol/L) and responses to the CDC questionnaire and other questions were examined using chi 2 statistical analysis. Two hundred ninety-nine women provided responses to questions about lead exposure risk. Thirty-nine women (13%) had elevated blood lead levels. A woman with a positive response to at least one CDC question was more likely to have elevated blood lead than a woman who answered negatively to all four CDC questions (relative risk = 2.39, 95% confidence interval 1.17-4.89; P = .01). Using the CDC definition of high risk ("yes" to at least one question), the questionnaire had a sensitivity of 75.7% and a negative predictive value of 93.1%. A questionnaire that combined housing conditions, smoking status, and high consumption of canned foods had a sensitivity of 89.2% and a negative predictive value of 96.4%. A high prevalence of elevated blood lead in children living with women with elevated blood lead was observed. Querying pregnant women about risk factors for lead exposure can aid in assessing prenatal lead exposure risk. The sensitivity and negative predictive value of the CDC questionnaire, when used with high-risk women, are comparable to its reported accuracy in young children.